Small, compact x-ray tubes have experienced widespread adoption in instruments for x-ray fluorescence (XRF) spectroscopy and x-ray diffraction (XRD) for a wide range of industrial, medical and dental applications. X-ray tubes conventionally emit radiation in a divergent manner. Obtaining an illumination spot size of sufficient intensity typically necessitated expensive, high-powered sources. The recent ability to focus x-ray radiation has enabled reductions in the size and cost of x-ray sources, and hence x-ray systems have been adopted in a variety of applications. X-ray beam production and transmission is exemplified by the polycapillary focusing and collimating optics and the in optic/source combinations such as those disclosed in commonly assigned, X-Ray Optical Systems, Inc. U.S. Pat. Nos. 5,192,869; 5,175,755; 5,497,008; 5,745,547; 5,570,408; and 5,604,353; and the above-identified U.S. patent applications—all of which are incorporated by reference herein in their entirety.
While progress in x-ray focusing has recently been achieved, further enhancements to x-ray source assemblies are still required. For example, improving the output stability of an x-ray beam under a variety of operating conditions, and calibration of their operation under known conditions. The present invention is directed to these requirements.